Spray wd40 along the plenum gasket. U will find ur problem.
Had to replace the inlet gasket on a 32 GTR the other week for this exact reason. My smoke tester proved my theory.
Had a constant miss in cylinder 2. Disconnect coil no difference. Disconnect injector slight difference. Spray wd40 or similar and idle cones good. Replaced with Nitto gaskets. Runs perfectly now.